X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=src%2Fguestfs.c;h=85a042a0a2eaf6b48d068f8e1d4ee0d854018e2f;hp=2ba062ce170c3fba43a023220717aabaf1ade696;hb=2a286f16215ebfac88a32d259f2b68191eb8d27e;hpb=cb9613b993792c1c4b14fa0d9b5001ff644ac2f4 diff --git a/src/guestfs.c b/src/guestfs.c index 2ba062c..85a042a 100644 --- a/src/guestfs.c +++ b/src/guestfs.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -85,17 +86,51 @@ #define safe_strdup guestfs_safe_strdup //#define safe_memdup guestfs_safe_memdup +#ifdef __linux__ +#define CAN_CHECK_PEER_EUID 1 +#else +#define CAN_CHECK_PEER_EUID 0 +#endif + static void default_error_cb (guestfs_h *g, void *data, const char *msg); static int send_to_daemon (guestfs_h *g, const void *v_buf, size_t n); static int recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn); static int accept_from_daemon (guestfs_h *g); static int check_peer_euid (guestfs_h *g, int sock, uid_t *rtn); static void close_handles (void); +static int qemu_supports (guestfs_h *g, const char *option); #define UNIX_PATH_MAX 108 -/* Also in guestfsd.c */ -#define GUESTFWD_ADDR "10.0.2.4" +#ifndef MAX +#define MAX(a,b) ((a)>(b)?(a):(b)) +#endif + +#ifdef __APPLE__ +#define xdr_uint32_t xdr_u_int32_t +#endif + +/* Network configuration of the appliance. Note these addresses are + * only meaningful within the context of the running appliance. QEMU + * translates network connections to these magic addresses into + * userspace calls on the host (eg. connect(2)). qemu-doc has a nice + * diagram which is also useful to refer to. + * + * NETWORK: The network. + * + * ROUTER: The address of the "host", ie. this library. + * + * [Note: If you change NETWORK and ROUTER then you also have to + * change the network configuration in appliance/init]. + * + * GUESTFWD_ADDR, GUESTFWD_PORT: The guestfwd feature of qemu + * magically connects this pseudo-address to the guestfwd channel. In + * typical Linux configurations of libguestfs, guestfwd is not + * actually used any more. + */ +#define NETWORK "169.254.0.0/16" +#define ROUTER "169.254.2.2" +#define GUESTFWD_ADDR "169.254.2.4" #define GUESTFWD_PORT "6666" /* GuestFS handle and connection. */ @@ -148,6 +183,8 @@ struct guestfs_h void * subprocess_quit_cb_data; guestfs_launch_done_cb launch_done_cb; void * launch_done_cb_data; + guestfs_close_cb close_cb; + void * close_cb_data; int msg_next_serial; }; @@ -259,6 +296,10 @@ guestfs_close (guestfs_h *g) if (g->verbose) fprintf (stderr, "closing guestfs handle %p (state %d)\n", g, g->state); + /* Run user close callback before anything else. */ + if (g->close_cb) + g->close_cb (g, g->close_cb_data); + /* Try to sync if autosync flag is set. */ if (g->autosync && g->state == READY) { guestfs_umount_all (g); @@ -389,7 +430,7 @@ guestfs_perrorf (guestfs_h *g, const char *fs, ...) if (err < 0) return; -#ifndef _GNU_SOURCE +#if !defined(_GNU_SOURCE) || defined(__APPLE__) char buf[256]; strerror_r (errnum, buf, sizeof buf); #else @@ -433,7 +474,11 @@ guestfs_safe_malloc (guestfs_h *g, size_t nbytes) /* Technically we should add an autoconf test for this, testing for the desired functionality, like what's done in gnulib, but for now, this is fine. */ +#if defined(__GLIBC__) #define HAVE_GNU_CALLOC (__GLIBC__ >= 2) +#else +#define HAVE_GNU_CALLOC 0 +#endif /* Allocate zeroed memory for N elements of S bytes, with error checking. S must be nonzero. */ @@ -791,9 +836,6 @@ int guestfs__add_drive_ro_with_if (guestfs_h *g, const char *filename, const char *drive_if) { - size_t len = strlen (filename) + 64; - char buf[len]; - if (strchr (filename, ',') != NULL) { error (g, _("filename cannot contain ',' (comma) character")); return -1; @@ -804,7 +846,24 @@ guestfs__add_drive_ro_with_if (guestfs_h *g, const char *filename, return -1; } - snprintf (buf, len, "file=%s,snapshot=on,if=%s", filename, drive_if); + if (qemu_supports (g, NULL) == -1) + return -1; + + /* Only SCSI and virtio drivers support readonly mode. + * This is only supported as a QEMU feature since 2010/01. + */ + int supports_ro = 0; + if ((STREQ (drive_if, "scsi") || STREQ (drive_if, "virtio")) && + qemu_supports (g, "readonly=on")) + supports_ro = 1; + + size_t len = strlen (filename) + 100; + char buf[len]; + + snprintf (buf, len, "file=%s,snapshot=on,%sif=%s", + filename, + supports_ro ? "readonly=on," : "", + drive_if); return guestfs__config (g, "-drive", buf); } @@ -870,17 +929,11 @@ dir_contains_files (const char *dir, ...) static void print_timestamped_message (guestfs_h *g, const char *fs, ...); static int build_supermin_appliance (guestfs_h *g, const char *path, char **kernel, char **initrd); -static int test_qemu (guestfs_h *g); -static int qemu_supports (guestfs_h *g, const char *option); static int is_openable (guestfs_h *g, const char *path, int flags); static void print_cmdline (guestfs_h *g); static const char *kernel_name = "vmlinuz." REPO "." host_cpu; static const char *initrd_name = "initramfs." REPO "." host_cpu ".img"; -static const char *supermin_name = - "initramfs." REPO "." host_cpu ".supermin.img"; -static const char *supermin_hostfiles_name = - "initramfs." REPO "." host_cpu ".supermin.hostfiles"; int guestfs__launch (guestfs_h *g) @@ -897,9 +950,21 @@ guestfs__launch (guestfs_h *g) char unixsock[256]; struct sockaddr_un addr; + /* Configured? */ + if (!g->cmdline) { + error (g, _("you must call guestfs_add_drive before guestfs_launch")); + return -1; + } + + if (g->state != CONFIG) { + error (g, _("the libguestfs handle has already been launched")); + return -1; + } + /* Start the clock ... */ gettimeofday (&g->launch_t, NULL); + /* Make the temporary directory. */ #ifdef P_tmpdir tmpdir = P_tmpdir; #else @@ -909,18 +974,6 @@ guestfs__launch (guestfs_h *g) tmpdir = getenv ("TMPDIR") ? : tmpdir; snprintf (dir_template, sizeof dir_template, "%s/libguestfsXXXXXX", tmpdir); - /* Configured? */ - if (!g->cmdline) { - error (g, _("you must call guestfs_add_drive before guestfs_launch")); - return -1; - } - - if (g->state != CONFIG) { - error (g, _("qemu has already been launched")); - return -1; - } - - /* Make the temporary directory. */ if (!g->tmpdir) { g->tmpdir = safe_strdup (g, dir_template); if (mkdtemp (g->tmpdir) == NULL) { @@ -929,6 +982,14 @@ guestfs__launch (guestfs_h *g) } } + /* Allow anyone to read the temporary directory. There are no + * secrets in the kernel or initrd files. The socket in this + * directory won't be readable but anyone can see it exists if they + * want. (RHBZ#610880). + */ + if (chmod (g->tmpdir, 0755) == -1) + fprintf (stderr, "chmod: %s: %m (ignored)\n", g->tmpdir); + /* First search g->path for the supermin appliance, and try to * synthesize a kernel and initrd from that. If it fails, we * try the path search again looking for a backup ordinary @@ -947,8 +1008,7 @@ guestfs__launch (guestfs_h *g) fprintf (stderr, "looking for supermin appliance in current directory\n"); if (dir_contains_files (".", - supermin_name, supermin_hostfiles_name, - "kmod.whitelist", NULL)) { + "supermin.d", "kmod.whitelist", NULL)) { if (build_supermin_appliance (g, ".", &kernel, &initrd) == -1) return -1; break; @@ -960,8 +1020,7 @@ guestfs__launch (guestfs_h *g) fprintf (stderr, "looking for supermin appliance in %s\n", pelem); if (dir_contains_files (pelem, - supermin_name, supermin_hostfiles_name, - "kmod.whitelist", NULL)) { + "supermin.d", "kmod.whitelist", NULL)) { if (build_supermin_appliance (g, pelem, &kernel, &initrd) == -1) return -1; break; @@ -1023,11 +1082,11 @@ guestfs__launch (guestfs_h *g) print_timestamped_message (g, "begin testing qemu features"); /* Get qemu help text and version. */ - if (test_qemu (g) == -1) + if (qemu_supports (g, NULL) == -1) goto cleanup0; /* Choose which vmchannel implementation to use. */ - if (qemu_supports (g, "-net user")) { + if (CAN_CHECK_PEER_EUID && qemu_supports (g, "-net user")) { /* The "null vmchannel" implementation. Requires SLIRP (user mode * networking in qemu) but no other vmchannel support. The daemon * will connect back to a random port number on localhost. @@ -1157,10 +1216,11 @@ guestfs__launch (guestfs_h *g) */ if (null_vmchannel_sock) { add_cmdline (g, "-net"); - add_cmdline (g, "user,vlan=0,net=10.0.2.0/8"); + add_cmdline (g, "user,vlan=0,net=" NETWORK); snprintf (buf, sizeof buf, - "guestfs_vmchannel=tcp:10.0.2.2:%d", null_vmchannel_sock); + "guestfs_vmchannel=tcp:" ROUTER ":%d", + null_vmchannel_sock); vmchannel = strdup (buf); } @@ -1183,7 +1243,7 @@ guestfs__launch (guestfs_h *g) add_cmdline (g, buf); snprintf (buf, sizeof buf, - "user,vlan=0,net=10.0.2.0/8," + "user,vlan=0,net=" NETWORK "," "guestfwd=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT "-chardev:guestfsvmc"); @@ -1203,7 +1263,7 @@ guestfs__launch (guestfs_h *g) add_cmdline (g, "-net"); add_cmdline (g, buf); add_cmdline (g, "-net"); - add_cmdline (g, "user,vlan=0,net=10.0.2.0/8"); + add_cmdline (g, "user,vlan=0,net=" NETWORK); vmchannel = "guestfs_vmchannel=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT; } @@ -1225,10 +1285,12 @@ guestfs__launch (guestfs_h *g) "%s " /* (selinux) */ "%s " /* (vmchannel) */ "%s " /* (verbose) */ + "TERM=%s " /* (TERM environment variable) */ "%s", /* (append) */ g->selinux ? "selinux=1 enforcing=0" : "selinux=0", vmchannel ? vmchannel : "", g->verbose ? "guestfs_verbose=1" : "", + getenv ("TERM") ? : "linux", g->append ? g->append : ""); add_cmdline (g, "-kernel"); @@ -1255,7 +1317,7 @@ guestfs__launch (guestfs_h *g) if (dup (wfd[0]) == -1) { dup_failed: perror ("dup failed"); - _exit (1); + _exit (EXIT_FAILURE); } if (dup (rfd[1]) == -1) goto dup_failed; @@ -1275,7 +1337,7 @@ guestfs__launch (guestfs_h *g) execv (g->qemu, g->cmdline); /* Run qemu. */ perror (g->qemu); - _exit (1); + _exit (EXIT_FAILURE); } /* Parent (library). */ @@ -1307,11 +1369,11 @@ guestfs__launch (guestfs_h *g) */ for (;;) { if (kill (qemu_pid, 0) == -1) /* qemu's gone away, we aren't needed */ - _exit (0); + _exit (EXIT_SUCCESS); if (kill (parent_pid, 0) == -1) { /* Parent's gone away, qemu still around, so kill qemu. */ kill (qemu_pid, 9); - _exit (0); + _exit (EXIT_SUCCESS); } sleep (2); } @@ -1371,6 +1433,7 @@ guestfs__launch (guestfs_h *g) "libguestfs: warning: unexpected connection from UID %d to port %d\n", uid, null_vmchannel_sock); close (sock); + sock = -1; continue; } } @@ -1465,7 +1528,7 @@ guestfs__launch (guestfs_h *g) close (wfd[1]); close (rfd[0]); } - kill (g->pid, 9); + if (g->pid > 0) kill (g->pid, 9); if (g->recoverypid > 0) kill (g->recoverypid, 9); waitpid (g->pid, NULL, 0); if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0); @@ -1535,12 +1598,20 @@ build_supermin_appliance (guestfs_h *g, const char *path, *initrd = safe_malloc (g, len + 8); snprintf (*initrd, len+8, "%s/initrd", g->tmpdir); + /* Set a sensible umask in the subprocess, so kernel and initrd + * output files are world-readable (RHBZ#610880). + */ snprintf (cmd, sizeof cmd, - "PATH='%s':$PATH " - "libguestfs-supermin-helper%s '%s' " host_cpu " " REPO " %s %s", - path, + "umask 0002; " + "febootstrap-supermin-helper%s " + "-k '%s/kmod.whitelist' " + "'%s/supermin.d' " + host_cpu " " + "%s %s", g->verbose ? " --verbose" : "", - path, *kernel, *initrd); + path, + path, + *kernel, *initrd); if (g->verbose) print_timestamped_message (g, "%s", cmd); @@ -1607,12 +1678,7 @@ test_qemu (guestfs_h *g) char cmd[1024]; FILE *fp; - free (g->qemu_help); - free (g->qemu_version); - g->qemu_help = NULL; - g->qemu_version = NULL; - - snprintf (cmd, sizeof cmd, "LC_ALL=C '%s' -help", g->qemu); + snprintf (cmd, sizeof cmd, "LC_ALL=C '%s' -nographic -help", g->qemu); fp = popen (cmd, "r"); /* qemu -help should always work (qemu -version OTOH wasn't @@ -1634,7 +1700,8 @@ test_qemu (guestfs_h *g) if (pclose (fp) == -1) goto error; - snprintf (cmd, sizeof cmd, "LC_ALL=C '%s' -version 2>/dev/null", g->qemu); + snprintf (cmd, sizeof cmd, "LC_ALL=C '%s' -nographic -version 2>/dev/null", + g->qemu); fp = popen (cmd, "r"); if (fp) { @@ -1672,11 +1739,26 @@ read_all (guestfs_h *g, FILE *fp, char **ret) /* Test if option is supported by qemu command line (just by grepping * the help text). + * + * The first time this is used, it has to run the external qemu + * binary. If that fails, it returns -1. + * + * To just do the first-time run of the qemu binary, call this with + * option == NULL, in which case it will return -1 if there was an + * error doing that. */ static int qemu_supports (guestfs_h *g, const char *option) { - return g->qemu_help && strstr (g->qemu_help, option) != NULL; + if (!g->qemu_help) { + if (test_qemu (g) == -1) + return -1; + } + + if (option == NULL) + return 1; + + return strstr (g->qemu_help, option) != NULL; } /* Check if a file can be opened. */ @@ -1700,6 +1782,7 @@ is_openable (guestfs_h *g, const char *path, int flags) static int check_peer_euid (guestfs_h *g, int sock, uid_t *rtn) { +#if CAN_CHECK_PEER_EUID struct sockaddr_in peer; socklen_t addrlen = sizeof peer; @@ -1768,6 +1851,12 @@ check_peer_euid (guestfs_h *g, int sock, uid_t *rtn) error (g, "check_peer_euid: no matching TCP connection found in /proc/net/tcp"); fclose (fp); return -1; +#else /* !CAN_CHECK_PEER_EUID */ + /* This function exists but should never be called in this + * configuration. + */ + abort (); +#endif /* !CAN_CHECK_PEER_EUID */ } /* You had to call this function after launch in versions <= 1.0.70, @@ -1795,7 +1884,7 @@ guestfs__kill_subprocess (guestfs_h *g) if (g->verbose) fprintf (stderr, "sending SIGTERM to process %d\n", g->pid); - kill (g->pid, SIGTERM); + if (g->pid > 0) kill (g->pid, SIGTERM); if (g->recoverypid > 0) kill (g->recoverypid, 9); return 0; @@ -1856,6 +1945,14 @@ guestfs_set_launch_done_callback (guestfs_h *g, g->launch_done_cb_data = opaque; } +void +guestfs_set_close_callback (guestfs_h *g, + guestfs_close_cb cb, void *opaque) +{ + g->close_cb = cb; + g->close_cb_data = opaque; +} + /*----------------------------------------------------------------------*/ /* This is the code used to send and receive RPC messages and (for @@ -1946,7 +2043,7 @@ child_cleanup (guestfs_h *g) if (g->verbose) fprintf (stderr, "child_cleanup: %p: child process died\n", g); - /*kill (g->pid, SIGTERM);*/ + /*if (g->pid > 0) kill (g->pid, SIGTERM);*/ if (g->recoverypid > 0) kill (g->recoverypid, 9); waitpid (g->pid, NULL, 0); if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0); @@ -1965,7 +2062,7 @@ child_cleanup (guestfs_h *g) } static int -read_log_message_or_eof (guestfs_h *g, int fd) +read_log_message_or_eof (guestfs_h *g, int fd, int error_if_eof) { char buf[BUFSIZ]; int n; @@ -1986,6 +2083,13 @@ read_log_message_or_eof (guestfs_h *g, int fd) if (n == 0) { /* Hopefully this indicates the qemu child process has died. */ child_cleanup (g); + + if (error_if_eof) { + /* We weren't expecting eof here (called from launch) so place + * something in the error buffer. RHBZ#588851. + */ + error (g, "child process died unexpectedly"); + } return -1; } @@ -2093,7 +2197,7 @@ send_to_daemon (guestfs_h *g, const void *v_buf, size_t n) } if (FD_ISSET (g->fd[1], &rset2)) { - if (read_log_message_or_eof (g, g->fd[1]) == -1) + if (read_log_message_or_eof (g, g->fd[1], 0) == -1) return -1; } if (FD_ISSET (g->sock, &rset2)) { @@ -2176,7 +2280,7 @@ recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn) } if (FD_ISSET (g->fd[1], &rset2)) { - if (read_log_message_or_eof (g, g->fd[1]) == -1) { + if (read_log_message_or_eof (g, g->fd[1], 0) == -1) { free (*buf_rtn); *buf_rtn = NULL; return -1; @@ -2313,8 +2417,16 @@ accept_from_daemon (guestfs_h *g) int sock = -1; while (sock == -1) { + /* If the qemu process has died, clean up the zombie (RHBZ#579155). + * By partially polling in the select below we ensure that this + * function will be called eventually. + */ + waitpid (g->pid, NULL, WNOHANG); + rset2 = rset; - int r = select (max_fd+1, &rset2, NULL, NULL, NULL); + + struct timeval tv = { .tv_sec = 1, .tv_usec = 0 }; + int r = select (max_fd+1, &rset2, NULL, NULL, &tv); if (r == -1) { if (errno == EINTR || errno == EAGAIN) continue; @@ -2323,7 +2435,7 @@ accept_from_daemon (guestfs_h *g) } if (FD_ISSET (g->fd[1], &rset2)) { - if (read_log_message_or_eof (g, g->fd[1]) == -1) + if (read_log_message_or_eof (g, g->fd[1], 1) == -1) return -1; } if (FD_ISSET (g->sock, &rset2)) {